Method of preparing a substrate with a composition including an organoborane initiator

ABSTRACT

A method of preparing a substrate with a composition comprising (i) an organoborane initiator and (ii) a radical curable component disposed thereon includes the step of depositing the composition onto the substrate wherein at least one of (i) the organoborane initiator and (ii) the radical curable component is deposited onto the substrate in the form of a gradient pattern. An article comprises the substrate and the gradient pattern formed on the substrate. The gradient pattern is formed from a developed composition comprising the reaction product of (i) the organoborane initiator and (ii) the radical curable component. By forming the gradient pattern on the substrate, combinatorial and high-throughput methods of generating and testing the developed composition are possible, which enable characterization of the developed composition for various physical and chemical properties.

CROSS-REFERENCE TO RELATED APPLICATIONS

The subject patent application claims priority to and all the benefitsof U.S. Provisional Patent Application Ser. No. 60/983,014 which wasfiled on Oct. 26, 2007, the entire specification of which is expresslyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to a method of preparing asubstrate. More specifically, the present invention is directed to amethod of preparing a substrate with a composition including reactivecomponents disposed thereon in the form of a gradient pattern.

DESCRIPTION OF THE RELATED ART

Recently, combinatorial and high-throughput methods of generating andtesting chemical compounds have attracted the attention of both industryand academia due to the potential for increasing productivity andreducing production costs associated with research and development. Asis known in the art, combinatorial chemical synthesis includes creatingmolecules in bulk and rapidly testing them for desirable properties.High-throughput methods are similar to combinatorial chemical methodsand involve using a brute-force approach to collect a large amount ofexperimental data related to molecules being tested. For example,high-throughput methods can be used to optimize chemical reactions bytesting matrices of different chemical reactants, catalysts, andconditions.

Both combinatorial and high-throughput methods have been utilized inpolymer synthesis and investigation in combination with parallelsynthesizers, microwave synthesizers, and ink-jet printers. Thesecombinations have allowed for the identification of fast and efficientoptimization of reaction conditions and for the testing of physicalproperties of the polymers.

One example of the use of combinatorial and high-throughput methods inpolymer science is disclosed in an article entitled “Combinatorial andHigh-Throughput Approaches in Polymer Science” Meas. Sci. Technol. 16(2005) 203-211. This article discloses using automated parallelsynthesizers, microwaves synthesizers, and inkjet printers to varycertain reaction parameters during polymer synthesis. Specifically,living radical polymerization reactions, emulsion polymerizations, andliving cationic ring-opening polymerizations are investigated relativeto monomers, catalysts, initiators, solvents, reactant ratios, andreaction temperatures.

Additional examples of the use of combinatorial and high-throughputchemistry, and specifically the use of inkjet printing techniques, aredisclosed in two additional scientific articles. A first article,entitled “Inkjet Printing of Polymer Micro-Arrays and Libraries:Instrumentation, Requirements, and Perspectives” Macromol. Rapid Commun.2003, 24, 659-666, discloses the use of inkjet printing in the field ofpolymer deposition and parallel synthesis of a large number of differentcompounds. This article discloses the commercially availableinstrumentation for ink-jet printing and corresponding requirements andexamines the use of ink-jet printing for the formation of multicolorpolymer light emitting diodes and polymer electronic devices. Thisarticle provides a general overview of the use of inkjet printing inpolymer deposition but does not disclose specific details about theapplication of these techniques to particular fields of polymer science.

The second article, entitled “Simple Modification of Sheet Resistivityof Conducting Polymeric Anodes Via Combinatorial Ink-Jet PrintingTechniques” Macromol. Rapid. Commun. 2005, 26, 238-246, discloses aprocess for fabricating microelectromechanical structures and electronicdevices such as organic thin film transistors, organicresistor-capacitor filers, and polymer capacitors. To fabricate thesedevices, ink-jet printing is used to deposit and pattern active polymerlayers onto anodes. More specifically, sheet resistivity of anodes ismodified by controlling ink-jet printers using color functionalitycorresponding to the deposition of different compounds.

Organoborane amine components are known in the art. For example,organoborane amine components used for the bulk polymerization ofacrylic monomers are described in U.S. Pat. No. 3,275,611 (Sep. 27,1966). Certain organoboron compounds such as trialkylboranes bythemselves, however, are pyrophoric in the presence of oxygen, sopreformed complexes between the organoboron compounds and aminecompounds are required to have the benefit of imparting improvedstability to organoboron compounds such as the trialkylboranes.

Recent modifications on the structure of organoborane amine componentsare described in U.S. Pat. No. 6,706,831 (Mar. 16, 2004), which alsodescribes use of the complexes in acrylate based adhesives. Thecombination of alkylborane-amine complexes with amine reactivedecomplexing agents to initiate the polymerization of acrylic adhesivesat room temperature is also described in the '831 patent. Suchcompositions offer the advantage of rapid cure and adhesion to lowenergy surfaces.

In view of the disclosure and teachings of the related art, thereremains an opportunity to provide a method of preparing a substrateincluding a composition disposed thereon using materials in thecomposition that, to date, have not been recognized as useable to formpatterns on substrates. There also remains an opportunity to developcombinatorial and high-throughput methods of generating and testing suchmaterials.

SUMMARY OF THE INVENTION AND ADVANTAGES

The present invention provides a method of preparing a substrate with acomposition disposed thereon. The composition comprises (i) anorganoborane initiator and (ii) a radical curable component. The methodcomprises the step of depositing the composition onto the substratewherein at least one of (i) the organoborane initiator and (ii) theradical curable component is deposited onto the substrate in the form ofa gradient pattern. The present invention also provides an article. Thearticle comprises the substrate and the gradient pattern formed on thesubstrate. The gradient pattern is formed from a developed compositioncomprising the reaction product of (i) the organoborane initiator and(ii) the radical curable component.

By forming the gradient pattern on the substrate, combinatorial andhigh-throughput methods of generating and testing the developedcomposition are possible, which enable characterization of the developedcomposition for various physical and chemical properties. For example,optimum physical and/or chemical properties of the developed compositionmay be quickly and efficiently determined by forming the gradientpattern and characterizing the developed composition at different pointsin the gradient pattern, whereby the gradient pattern enables preciseamounts of (i) the organoborane initiator and (ii) the radical curablecomponent to be correlated to the characterized physical and/or chemicalproperty.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated,as the same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 a is an image of a gradient pattern that is 319 pixels wide by1200 pixels long, that increases progressively from 100 to 0% black, andthat is prepared using Adobe Photoshop® Elements software;

FIG. 1 b is an image of another gradient pattern illustrating discretepixels based on inkjet droplet volume and is created from FIG. 1 a usingan Adobe Photoshop® plug in commercially available from Xaar®;

FIG. 1 c is an image of yet another gradient pattern based on inkjetdroplet volume and droplet placement on a substrate and is developedfrom FIG. 1 b using the Adobe Photoshop® plug in commercially availablefrom Xaar®;

FIG. 2 a is an optical micrograph of droplets of commercially availableblack ink dispensed onto photopaper in a single pass using a Xenjet®4000 industrial inkjet printer illustrating that the inkjet printerprints rows of droplets with only a single pass;

FIG. 2 b is an optical micrograph of a continuous film formed fromdroplets of commercially available black ink dispensed onto photopaperin four passes using the Xenjet® 4000 industrial inkjet printer and aprinthead that is offset 50 μm per pass illustrating that the inkjetprinter can form a continuous film using multiple passes; and

FIG. 3 is a collection of optical micrographs of the gradient pattern ofFIG. 1 c printed onto photopaper in four passes using commerciallyavailable black ink, the Xenjet® 4000 industrial inkjet printer, and aprinthead that is offset 50 μm per pass illustrating that a density ofdeposited ink decreases from left to right across the photopaper andacross the micrographs and that this gradient pattern printed with thisinkjet printer can be used to form a gradient pattern in the instantinvention.

DETAILED DESCRIPTION OF THE INVENTION

A method of preparing a substrate and an article including the substrateand a gradient pattern formed thereon, are provided. The substrate isprepared with a composition including (i) an organoborane initiator and(ii) a radical curable component, among other optional components suchas (iii) a decomplexing component. In one embodiment, the compositioncomprises a mixture of the organoborane initiator and the radicalcurable component that is separated from the decomplexing agent. Inanother embodiment, the composition comprises a first mixture includingthe organoborane initiator and a first amount of the radical curablecomponent and a second mixture including a second amount of the radicalcurable component and the decomplexing component. It is to be understoodthat the composition may include any combination of the organoboraneinitiator, the radical curable component, and the decomplexing componentso long as the organoborane initiator and the decomplexing component arenot stored together or combined before reaction and cure is desired.

The gradient pattern is formed on the substrate by depositing thecomposition on the substrate wherein at least one of the organoboraneinitiator and the radical curable component is deposited on thesubstrate in the form of the gradient pattern. In an alternativeembodiment, the gradient pattern is formed by depositing at least one ofthe organoborane initiator, the radical curable component, and thedecomplexing component on the substrate in the form of the gradientpattern. The composition cures or develops at reduced temperatures andcan be utilized in a wide range of curing conditions due to an abilityto develop more rapidly in deep and confined areas, thereby reducingproduction costs and energy expenditure associated with operating curingovens and/or long curing cycles. The composition, after developing, isalso resistant to inhibitors of Pt-group hydrosilylation catalysts andexhibits increased thermal stability. The composition also contributesto formation of a substantially developed surface, thereby decreasingsurface wetness. The composition also rapidly cross-links and may bondto various materials at reduced temperatures including, but not limitedto, plastics, metals, and other inorganic surfaces. Rapid cross-linkingand an ability of the composition to bond to various materials atreduced temperatures increases production efficiency and speed andfurther reduces production costs and energy expenditure associated withheating.

The method and the article of the present invention are useful fordetermining optimum physical and/or chemical properties of the developedcomposition. In particular, the method is useful for testing andanalytical purposes to correlate amounts or types of organoboraneinitiators, decomplexing components, and radical curable components tocertain physical and/or chemical properties of the resulting compositionafter development or curing. This is possible due to the formation ofthe gradient pattern.

The gradient pattern is more specifically defined as a pattern with aprogressive change (increase) in surface coverage of at least one of theorganoborane initiator, the radical curable component, and/or thedecomplexing component, varying along a linear axis on the surface ofthe substrate. It is also contemplated that optional components may alsobe included with the organoborane initiator, the radical curablecomponent, and/or the decomplexing component. More specifically, thepattern exhibits a gradient in composition.

In forming the gradient pattern, the variation in the surface coverageis typically a monotonic variation of from 0 to 100%, or any rangesin-between and one or more of the organoborane initiator, the radicalcurable component, and/or the decomplexing component may be varied alongone linear or curvilinear axis of the surface. It is contemplated thatbetween upper and lower bounds of surface coverage, the coverage of theorganoborane initiator, the decomplexing component, and/or the radicalcurable component may be linear or non-linear and is preferablymonotonic and controlled in variation. Further, two or more of theorganoborane initiator, the decomplexing component, and/or the radicalcurable component may be varied along linear axes that are perpendicularto each other, which results in a larger number of combinations betweenamount and type of component on the substrate as compared to variationof the amount and type of component along a single axis. For example, inone embodiment, the gradient pattern, prior to reaction, is furtherdefined as surface coverage of the organoborane initiator on thesubstrate varying from 0 to 100% along a first axis and surface coverageof the decomplexing component on the substrate varying from 0 to 100%along a second axis transverse to the first axis. In another embodiment,the gradient pattern is further defined as surface coverage of at leastone of the organoborane initiator and the radical curable component onthe substrate increasing progressively from 0 to 100% along a firstaxis. In this embodiment, the gradient pattern may be further defined assurface coverage of the decomplexing component on the substrateincreasing progressively from 0 to 100% along a second axis transverseto the first axis. In yet another embodiment, the gradient pattern isfurther defined as surface coverage of at least one of the organoboraneinitiator, the radical curable component, and the decomplexing componenton the substrate increasing progressively from 0 to 100% along a firstaxis. In this embodiment, the gradient pattern may be further defined assurface coverage of at least one of the organoborane initiator, theradical curable component, and the decomplexing component on thesubstrate increasing progressively from 0 to 100% along a second axistransverse to the first axis, so long as the at least one of theorganoborane initiator, the radical curable component, and thedecomplexing component along the second axis is not the same as the atleast one of the organoborane initiator, the radical curable component,and the decomplexing component along the first axis. As just oneexample, if the organoborane initiator is deposited on the substrate ina gradient pattern increasing progressively from 0 to 100% along a firstaxis (e.g. the x-axis), there may be surface coverage of the radicalcurable component and/or the decomplexing component on the substrateincreasing progressively from 0 to 100% along a second axis (e.g. they-axis) transverse to the first axis. Physical and/or chemicalproperties of the resulting composition, after curing, can be tested andthe specific amounts of the organoborane initiator and the decomplexingcomponent, for example, can be correlated to the physical and/orchemical properties that are measured.

Referring back, the organoborane initiator may be any organoborane knownin the art capable of generating free radicals. Typically, theorganoborane initiator is derived from decomplexation of an air-stablecomplex of an organoborane and an organonitrogen compound. In oneembodiment, the organoborane has the general structure:

wherein each of R1-R3 independently has from 1 to 20 carbon atoms; andwherein each of R1-R3 is independently selected from the group of ahydrogen, an aliphatic hydrocarbon group, and an aromatic hydrocarbongroup. Specific examples of the organoborane represented by the formulaabove include those selected from the group of tri-methylborane,tri-ethylborane, tri-n-butylborane, tri-n-octylborane,tri-sec-butylborane, tridodecylborane, phenyldiethylborane, andcombinations thereof. Typically, the organoborane comprisestri-n-butylborane. More specifically, while the organoborane of thepresent invention may include a combination of specific organoboranes,one of the organoboranes is typically tri-n-butylborane. In anotherembodiment, the organoborane is organosilicon functional. Morespecifically, the organoborane may have a similar structure to thestructure set forth above, but at least one of the functional groupspending from the boron atom may include, for example, a silicon atom, asiloxane oligomer, or a siloxane polymer. Such organosilicon functionalorganoboranes are described in PCT Publication No. WO06073695A1, theportions of which describe organosilicon functional organoboranes arehereby incorporated by reference.

In an alternative embodiment, the organoborane initiator is furtherdefined as an organoborane-organonitrogen complex. Suitableorganoborane-organonitrogen complexes include, but are not limited to,organoborane-amine complexes, organoborane-azole complexes,organoborane-amidine complexes, organoborane-heterocyclic nitrogencomplexes, amidoorganoborate complexes, and combinations thereof.Additional suitable organoborane initiators are described in U.S. Pat.App. Pub. No. 2007/0141267, U.S. Pat. No. 7,247,596, and WO Publication.No. 2007/044735, expressly incorporated herein by reference relative tothe organoborane initiators. In one embodiment, the organoboraneinitiator is further defined as a complex of an organoborane and anamine, i.e., an organoborane-amine complex. The organoborane-aminecomplex may comprise a trialkylborane-amine complex. A typicalorganoborane-amine complex includes a complex formed between anorganoborane and a suitable amine that renders the organoborane-aminecomplex stable at ambient conditions. Any organoborane-amine complexknown in the art may be used. Typically, the organoborane-amine complexis capable of initiating polymerization or cross-linking of the radicalcurable component through introduction of an amine-reactive compound,and/or by heating. That is, the organoborane-amine complex may bedestabilized at ambient temperatures through exposure to suitableamine-reactive compounds.

The organoborane-amine complex typically has the formula:

wherein B represents boron. Additionally, each of R⁴, R⁵, and R⁶ istypically independently selected from the group of a hydrogen atom, acycloalkyl group, a linear or branched alkyl group having from 1 to 12carbon atoms in a backbone, an alkylaryl group, an organosilane group,an organosiloxane group, an alkylene group capable of functioning as acovalent bridge to the boron, a divalent organosiloxane group capable offunctioning as a covalent bridge to the boron, and halogen substitutedhomologues thereof, such that at least one of R⁴, R⁵, and R⁶ includesone or more silicon atoms, and is covalently bonded to boron. Further,each of R⁷, R⁸, and R⁹ typically yields an amine compound or a polyaminecompound capable of complexing the boron. Two or more of R⁴, R⁵, and R⁶and two or more of R⁷, R⁸, and R⁹ typically combine to form heterocyclicstructures, provided a sum of the number of atoms from R⁴, R⁵, R⁶, R⁷,R⁸, and R⁹ does not exceed 11.

Some examples of amines that are suitable for complexing with theorganoborane in the organoborane-amine complex include organic aminecompounds such as 1,3 propane diamine, 1,6-hexanediamine,methoxypropylamine, pyridine, and isophorone diamine. Alternatively, theamine may include a group selected from an alkyl group, an alkoxy group,an imidazole group, an amidine group, an ureido group, and combinationsthereof. Other examples of suitable amine are described in U.S. Pat.Nos. 6,777,512 and 6,806,330, which are expressly incorporated byreference herein relative to the amines. Yet other examples of suitableamines include silicon containing amines selected from the group ofamine-functional silanes, amine-functional organopolysiloxanes, andcombinations thereof. Specific examples of amine-functional silanes thatare suitable for purposes of the present invention include aminosilanessuch as 3-aminomethyltrimethoxysilane, 3-aminopropyltrimethoxysilane,3-aminomethyltriethoxysilane, 3-aminopropyltriethoxysilane,2-(trimethoxysilylethyl)pyridine, aminopropylsilanetriol,3-(m-aminophenoxy)propyltrimethoxysilane,3-aminopropyldiisopropylmethoxysilane, aminophenyltrimethoxysilane,3-aminopropyltris(methoxyethoxethoxy)silane,N-(2-aminoethyl)-3-aminomethyltrimethoxysilane,N-(2-aminoethyl)-3-aminopropyltrimethoxysilane,N-(6-aminohexyl)aminomethyltrimethoxysilane,N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane,(aminoethylaminomethyl)phenethyltrimethoxysilane,N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane,N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, and(3-trimethoxysilylpropyl)diethylene-triamine.

Amine-functional organopolysiloxanes that are suitable for purposes ofthe present invention include organosilicon compounds described below informulas (a) and (b), and those compounds described herein asorganopolysiloxane resins, subject to the stipulation that theorganopolysiloxanes contain at least one amine functional group such as3-aminopropyl, aminomethyl, 2-aminoethyl, 6-aminohexyl, 11-aminoundecyl,3-(N-allylamino)propyl, N-(2-aminoethyl)-3-aminopropyl,N-(2-aminoethyl)-3-aminoisobutyl, p-aminophenyl, 2-ethylpyridine, and3-propylpyrrole.

Specific examples of organopolysiloxanes that are suitable for purposesof the present invention include terminal and/or pendantamine-functional polydimethylsiloxane oligomers and polymers, terminaland/or pendant amine-functional random, graft and block copolymers andco-oligomers of polydimethylsiloxane and poly(3,3,3trifluoropropyl-methylsiloxane), terminal and/or pendantamine-functional random, graft and block copolymers and co-oligomers ofpolydimethylsiloxane andpoly(6,6,6,5,5,4,4,3,3-nonfluorohexyl-methylsiloxane), and terminaland/or pendant amine-functional random, graft and block copolymers andco-oligomers of polydimethylsiloxane and polyphenymethylsiloxane. Otherexamples of useful compounds include resinous amine-functional siloxanessuch as the amine-functional compounds described herein asorganopolysiloxane resins, as well as amine-functionalpolysilsesquioxanes.

Other nitrogen containing compounds may also be complexed with theorganoborane, such as compounds selected from the group ofN-(3-triethyoxysilylpropyl)-4,5-dihydroimidazole,ureidopropyltriethoxysilane, siloxanes of formulas similar to formulas(a) and (b) so long as they include at least one nitrogen atom, andthose compounds described herein as organopolysiloxane resins in whichat least one group is an imidazole, amidine, or ureido functional group.When the amine or organonitrogen compound is polymeric, the molecularweight is not limited, except that it should be such as to maintain asufficiently high concentration of boron to permit polymerization of thecomposition.

The organoborane initiator may be physically and/or chemically attached(bound) to a solid particle such as a phase support to control workingtimes, as well as to stabilize liquid phase organoborane-amine complexesagainst separating during storage. Attachment can be accomplished by anumber of known surface treatments either in-situ or a priori. Somesurface treatment methods include pre-treating solid particles such asground or precipitated silica, calcium carbonate, carbon black, carbonnanoparticles, silicon nanoparticles, barium sulfate, titanium dioxide,aluminum oxide, boron nitride, silver, gold, platinum, palladium, andalloys thereof, base metals such as nickel, aluminum, copper, and steel,and combinations thereof, with a condensation reactive compound. Someexamples of condensation reactive compounds that may be used include,but are not limited to, aminopropyltrimethoxysilane,isocyanatopropyltriethoxysilane, isocyanatomethyltriethoxysilane,triethoxysilylundecanal, glycidoxypropyltrimethoxysilane,glycidoxymethyltrimethoxysilane, 3-(triethoxysilyl)propylsuccinicanhydride, 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane, andcombinations thereof. Although it is typically desirable to control theparticle size and particle size distribution to impart the desiredproperties, the size of the particles is not inherently limited, and canrange from discrete nanoparticles, i.e., nanometer diameter, toagglomerated or fused structures up to millimeter size. The pretreatmentmay be followed by complexation with the organoborane, or by directtreatment of the solid particles using a preformed organoboraneinitiator that is condensation reactive. If the solid particles includesurface functional groups, additives such as surface treating agents orimpurities that are inherently amine-reactive, may require appropriatepre-cautions to avoid premature decomplexation of the organoboraneinitiator being attached. Solid particles including amine-reactivesubstances can be purified or neutralized before attachment of theorganoborane initiator. Alternatively, the attachment of theorganoborane initiator may be performed in an oxygen free environment.

While about 100% by weight of the organoborane initiator is typicallythe organoborane-organonitrogen complex or the organoborane-aminecomplex, it is to be appreciated that other compounds, such asimpurities and other compounds known in the art to be commonly presentwith the organoborane initiator, may also be present such that less than100% by weight of the organoborane initiator is theorganoborane-organonitrogen complex or the organoborane-amine complex.The organoborane initiator is typically present in the composition in anamount sufficient to provide a concentration of boron of from 100 and10,000 parts by weight, more typically from 300 to 3,000 parts byweight, per one million weight parts of the radical curable componentpresent in the composition.

It is to be understood that an overall concentration of the organoboraneinitiator may be deliberately varied across the gradient pattern bychanging surface coverage of the organoborane initiator that isdeposited on the substrate in a systematic manner along one axis of thesurface. Hence, the overall concentration range of the organoboraneinitiator on the substrate, based upon the combined weight of allcomponents, can range from zero to 100%.

Referring back, the decomplexing component may include an organonitrogenreactive compound (e.g. an amine reactive compound) that is capable ofreacting with the organonitrogen (e.g. the amine) in the organoboraneinitiator. The decomplexing component may be a small molecule, amonomer, an oligomer, a polymer, or a mixture thereof, and may also bediluted or borne by a carrier such as an aqueous or non-aqueous solvent,or by a filler particle. In one embodiment, wherein the organoboraneinitiator is further defined as an organoborane-organonitrogen complex,the decomplexing component allows pattern development to occur rapidlyat temperatures below the dissociation temperature of theorganoborane-organonitrogen complex, including room temperature andbelow. The decomplexing component may be deposited onto the substrate asa liquid, gas, or solid.

Examples of suitable amine reactive- and organonitrogenreactive-compounds that may be included in the decomplexing componentinclude those selected from the group of mineral acids, Lewis acids,carboxylic acids, carboxylic acid derivatives such as anhydrides andsuccinates, carboxylic acid salts, isocyanates, aldehydes, epoxides,acid chlorides, sulphonyl chlorides, iodonium salts, anhydrides, andcombinations thereof. Some specific examples include compounds selectedfrom the group of acrylic acid, methacrylic acid, polyacrylic acid,polymethacrylic acid, methacrylic anhydride, 2-carboxyethyl acrylate,2-carboxyethyl methacrylate, undecylenic acid, acetic acid, oleic acid,lauric acid, lauric anhydride, citraconic anhydride, ascorbic acid(Vitamin C), isophorone diisocyanate monomers or oligomers,methacryloylisocyanate, 2-(methacryloyloxy)ethyl acetoacetate,undecylenic aldehyde, dodecyl succinic anhydride, and combinationsthereof.

Further examples include compounds selected from the group of silanes,organosiloxanes, and combinations thereof. Some examples of suitableorganosilanes include those selected from the group of3-isocyanatopropyltrimethoxysilane, 3-isocyanatomethyltrimethoxysilane,3-glycidoxypropyltrimethoxysilane, and combinations thereof. Otherorganosilicon compounds that can be used include those selected from thegroup of triethoxysilylpropyl succinic anhydride; propylsuccinicanhydride functionalized linear, branched, resinous, and hyperbranchedorganopolysiloxanes; methylsuccinic anhydride functionalized linear,branched, resinous, and hyperbranched organopolysiloxanes; cyclohexenylanhydride functional linear, resinous, and hyperbranchedorganopolysiloxanes; carboxylic acid functionalized linear, branched,resinous, and hyperbranched organopolysiloxanes such as carboxydecylterminated oligomeric or polymeric polydimethylsiloxanes; and aldehydefunctionalized linear, branched, resinous, and hyperbranchedorganopolysiloxanes such as undecylenic aldehyde-terminated oligomericor polymeric polydimethylsiloxanes; and combinations thereof.

U.S. Pat. No. 6,777,512 describes silicon containing compounds that canbe used in the decomplexing component including certain compounds thatrelease an acid when exposed to moisture. The '512 patent also describesamine reactive compounds referred to as decomplexation agents that canbe used in the decomplexing component. U.S. Pat. No. 6,777,512 is herebyexpressly incorporated by reference relative to the silicon containingcompound and the decomplexation agents described above.

Although a notable advantage of the method of the present invention israpid ambient temperature development of patterns without the need for aradiation source, the composition may be used to create patterns usingexisting radiative processes such as under a UV or e-beam source toaccelerate reaction, enable curing in shadowed regions or in deepsections, or to impart improved adhesion to the substrate. In suchcases, it may be useful to include compounds in the decomplexingcomponent that are capable of generating organonitrogen- oramine-reactive groups when exposed to ultraviolet radiation, such as aphotoacid generator. Examples of such compounds include iodonium saltscontaining [SbF₆]⁻ counter ions. In such an embodiment, it may be usefulto optionally include a photosensitizing compound such asisopropylthioxanthone.

While about 100% by weight of the decomplexing component is typicallythe organonitrogen- or amine-reactive compound, it is to be appreciatedthat other compounds, such as impurities and other compounds known inthe art to be commonly present with the organonitrogen- oramine-reactive compound, may also be present such that less than 100% byweight of the decomplexing component is the organonitrogen- oramine-reactive compound.

The relationship between the organoborane initiator and the decomplexingcomponent enables development, virtually instantaneously, of a range ofradical curable components such as unsaturated monomers. The radicalcurable component can include an organic compound, such as an acryliccompound, or an organometallic compound, such as a radical curableorganosilicon compound. In either case, the radical curable componentcan include a single monomer, oligomer, or polymer containingunsaturation and capable of undergoing free radical polymerization.Mixtures of monomers, oligomers, and polymers can also be used. In oneembodiment, the radical curable component includes a first radicalpolymerizable (curable) monomer and a second radical polymerizable(curable) monomer which may be combined or may be separated. Themixtures may be used to impart a desired combination of physicalproperties such as viscosity, volatility, substrate wetting forprocessability and resolution in an uncured state, glass transitiontemperature, hardness or solubility, and surface properties such ashydrophilicity or hydrophobicity in the cured state. When the radicalcurable component includes an organic compound, the selected compoundwill depend on the use of the cured product. Examples of suitableorganic compounds are described in U.S. Pat. No. 6,762,260, includingorganic compounds such as 2-ethylhexylacrylate,2-ethylhexylmethacrylate, methylacrylate, methylmethacrylate, neopentylglycol diacrylate, neopentyl glycol dimethacrylate, glycidyl acrylate,glycidyl methacrylate, allyl acrylate, allyl methacrylate, stearylacrylate, stearyl methacrylate, tetrahydrofurfuryl methacrylate,caprolactone acrylate, perfluorobutyl acrylate, perfluorobutylmethacrylate, 1H,1H,2H,2H-heptadecafluorodecyl acrylate,1H,1H,2H,2H-heptadecafluorodecyl methacrylate, tetrahydroperfluoroacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, bisphenol Aacrylate, bisphenol A dimethacrylate, ethoxylated bisphenol A acrylate,ethoxylated bisphenol A methacrylate, hexafluoro bisphenol A diacrylate,hexafluoro bisphenol A dimethacrylate, diethylene glycol diacrylate,diethylene glycol dimethacrylate, dipropylene glycol diacrylate,dipropylene glycol dimethacrylate, polyethylene glycol diacrylate,polyethylene glycol dimethacrylate, polypropylene glycol diacrylate,polypropylene glycol dimethacrylate, trimethylolpropane triacrylate,trimethylolpropane trimethacrylate, ethoxylated trimethylolpropanetriacrylate, ethoxylated trimethylolpropane trimethacrylate),pentaerythritol triacrylate, pentaerythritol trimethacrylate),pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate,methyl-3-butenoate, allyl methyl carbonate, diallyl pyrocarbonate, allylacetoacetate, diallyl carbonate, diallyl phthalate, dimethyl itaconate,diallyl carbonate, and combinations thereof. Other suitable organiccompounds include acrylate tipped polyurethane prepolymers prepared byreacting isocyanate reactive acrylate monomers, oligomers or polymerssuch as hydroxy acrylates with isocyanate functional prepolymers. U.S.Pat. No. 6,762,260 is expressly incorporated herein by referencerelative to the organic compounds.

Also suitable for use in the radical curable component are a class ofconductive monomers, dopants, oligomers, polymers, and macromonomershaving an average of at least one free radical polymerizable group permolecule, and the ability to transport electrons, ions, holes, and/orphonons. For example, U.S. Pat. No. 5,929,194 describes the preparationof various free radical polymerizable hole transporting compounds suchas4,4′4″-tris[N-(3(2-acryloyoxyethyloxy)phenyl)-N-phenylamino]triphenylamineand 4,4′4″-tris[N-(3(benzoyloxyphenyl)-N-phenylamino]triphenylamine, andpreparation of electroluminescent devices made therefrom. U.S. Pat. No.5,929,194 is also expressly incorporated herein by reference relative tothe free radical polymerizable hole transporting compounds introducedabove. It is noted that the acrylic functional group prefixes acryloyl-and acryl- are used interchangeably herein, as are the methacrylicfunctional group prefixes methacryloyl- and methacryl-.

When an organosilicon compound is used in the radical curable component,again the selected compound depends on the use of the cured product.Generally, the organosilicon compound comprises organosilanes ororganopolysiloxanes having on average at least one free radicalpolymerizable moiety. The organosilicon compound can be monomeric,oligomeric, polymeric, or it can be a mixture of monomers, and/oroligomers, and/or polymers. Higher molecular weight species of such freeradical polymerizable compounds are often referred to in the art asmacromonomers. The organosilicon compounds can contain mono-functionalor multi-functional units in the free radical polymerizable group. Thisallows for polymerization of the organosilicon compounds to linearpolymers, branched polymers of various architecture, copolymers ofvarious architecture, or crosslinked polymeric networks. The monomersand oligomers can be any monomer or oligomer normally used to prepareaddition or condensation curable polymers, or they can be monomers oroligomers used in other types of curing reactions, provided they containat least one free radical polymerizable group.

Suitable organosilicon monomers include compounds having a structuregenerally corresponding to the formula R″_(n)Si(OR′″)_(4-n), where n is0-4; and where at least one of the R″ or R′″ groups contains a freeradical polymerizable group. The R″ and R′″ groups can be independently,hydrogen; a halogen atom; or an organic group including alkyl groups,haloalkyl groups, aryl groups, haloaryl groups, alkenyl groups, alkynylgroups, acrylate functional groups, and methacrylate functional groups.The R″ and R′″ groups may also contain other organic functional groupsincluding glycidyl groups, amine groups, ether groups, cyanate estergroups, isocyano groups, ester groups, carboxylic acid groups,carboxylate salt groups, succinate groups, anhydride groups, mercaptogroups, sulfide groups, azide groups, phosphonate groups, phosphinegroups, masked isocyano groups, and hydroxyl groups.

Representative examples of free radical polymerizable organosiliconmonomers include compounds such as 3-methacryloxypropyltrimethoxysilane,3-methacryloxymethyltrimethoxysilane,3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane,3-acryloxymethyltrimethoxysilane, 3-methacryloxypropyltrimethylsilane,3-acryloxypropyltriethoxysilane, 3-acryloxylpropyltrimethylsilane,vinyltrimethoxysilane, allyltrimethoxysilane, 1-hexenyltrimethoxysilane,tetra-(allyloxysilane), tetra-(3-butenyl-1-oxy)silane,tri-(3-butenyl-1-oxy)methylsilane, di-(3-butenyl-1-oxy)dimethylsilane,and 3-butenyl-1-oxy trimethylsilane. Other examples include di-alkoxyfunctional analogs of the trialkoxysilanes exemplified above, such as3-methacryloxypropylmethyldimethoxysilane, mono-alkoxy functionalanalogs of the above, such as 3-methacryloxypropyldimethylmethoxysilane.Also included within this class are halosilane precursors of thesemonomers, such as 3-methacryloxypropyltrichlorosilane,3-methacryloxypropylmethyldichlorosilane, and3-methacryloxypropyldimethylchlorosilane. The preferred radicalpolymerizable moieties for these organosilicon compounds are aliphaticunsaturated groups in which the double bond is located at the terminalpositions, internal positions, or both positions relative to thefunctional group. The most preferred radical polymerizable moieties forthe organosilicon compounds are acrylate groups or methacrylate groups.

When the radical curable component includes an organosilicon monomer,oligomer, or polymer, the radical curable component can be anorganopolysiloxane having a linear, branched, hyperbranched, or resinousstructure. The radical curable component can be homopolymeric orcopolymeric. The radical polymerizable moiety for the organopolysiloxanecan be an unsaturated organic group such as an alkenyl group having 2-12carbon atoms, exemplified by the vinyl group, allyl group, butenylgroup, or the hexenyl group. The unsaturated organic group can alsocomprise alkynyl groups having 2-12 carbon atoms, exemplified by theethynyl group, propynyl group, or the butynyl group. The unsaturatedorganic group can bear the radical polymerizable group on an oligomericor polymeric polyether moiety such as an allyloxypoly(oxyalkylene) groupor a halogen substituted analog thereof. The radical polymerizableorganic group can contain acrylate functional groups or methacrylatefunctional groups, exemplified by acryloxyalkyl groups such asacryloxymethyl and acryloxypropyl groups, and methacryloxyalkyl groupssuch as methacryloxymethyl and methacryloxypropyl groups. Theunsaturated organic groups can be located at the terminal positions,pendant positions, or both the terminal and pendant positions relativeto the polymer backbone. The preferred radical polymerizable moiety formonomeric, oligomeric, and polymeric organosilicon compounds areacrylate groups and methacrylate groups.

Any remaining silicon bonded organic groups can be monovalent organicgroups free of aliphatic unsaturation. The monovalent organic group canhave 1-20 carbon atoms, preferably 1-10 carbon atoms, and is exemplifiedby alkyl groups such as methyl, ethyl, propyl, pentyl, octyl, undecyl,and octadecyl; cycloalkyl groups such as cyclohexyl; aryl groups such asphenyl, tolyl, xylyl, benzyl, and 2-phenylethyl;alkyloxypoly(oxyalkylene) groups such as propyloxypoly(oxyethylene),propyloxypoly(oxypropylene),propyloxy-poly(oxypropylene)-co-poly(oxyethylene) groups, halogensubstituted analogs thereof; cyano functional groups includingcyanoalkyl groups such as cyanoethyl and cyanopropyl; carbazole groupssuch as 3-(N-carbazolyl)propyl; arylamino-functional groups such as4-(N,N-diphenylamino)phenyl-3-propyl; and halogenated hydrocarbon groupssuch as 3,3,3-trifluoropropyl, 3-chloropropyl, dichlorophenyl, and6,6,6,5,5,4,4,3,3-nonafluorohexyl.

The radical curable component that includes the organosilicon compoundcan vary in consistency from a fluid having a viscosity of 0.001 Pa·s at25° C. to a gum. The radical curable component that is the organosiliconcompound can also be a solid that becomes flowable at an elevatedtemperature or by the application of shear.

The radical curable component may include organopolysiloxane fluidshaving the formulae:R¹ ₃SiO(R¹ ₂SiO)_(a)(R¹R²SiO)_(b)SiR¹ ₃,  (a)R³ ₂R⁴SiO(R³ ₂SiO)_(c)(R³R⁴SiO)_(d)SiR³ ₂R⁴, or  (b)

-   -   (c) combinations of such fluids.

In Formula (a), a has an average value of zero to 20,000, b has anaverage value of from 1-20,000, c has an average value of zero to20,000, and d has an average value of zero to 20,000. Each R¹ group isindependently a monovalent organic group. The R² group is independentlyan unsaturated monovalent organic group. The R³ groups can be the sameas the R¹ groups. Each R⁴ group is independently an unsaturated organicgroup.

Suitable R¹ groups are monovalent organic groups including acrylicfunctional groups such as acryloxymethyl, acryloxypropyl,methacryloxymethyl, methacryloxypropyl groups; alkyl groups such asmethyl, ethyl, propyl, and butyl groups; alkenyl groups such as vinyl,allyl, and butenyl groups; alkynyl groups such as ethynyl and propynylgroups; aromatic groups such as phenyl, tolyl, and xylyl groups;cyanoalkyl groups such as cyanomethyl, cyanoethyl and cyanopropylgroups; halogenated hydrocarbon groups such as 3,3,3-trifluoropropyl,3-chloropropyl, dichlorophenyl, and 6,6,6,5,5,4,4,3,3-nonafluorohexylgroups; alkenyloxypoly(oxyalkyene) groups such asallyloxy(polyoxyethylene), allyloxypoly(oxypropylene), andallyloxy-poly(oxypropylene)-co-poly(oxyethylene) groups;alkyloxypoly(oxyalkyene) groups such as propyloxy(polyoxyethylene),propyloxypoly(oxypropylene), andpropyloxy-poly(oxypropylene)-co-poly(oxyethylene) groups; halogensubstituted alkyloxypoly(oxyalkyene) groups such asperfluoropropyloxy(polyoxyethylene),perfluoropropyloxypoly(oxypropylene), andperfluoropropyloxy-poly(oxypropylene)-co-poly(oxyethylene) groups;alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy,and ethylhexyloxy groups; aminoalkyl groups such as 3-aminopropyl,6-aminohexyl, 11-aminoundecyl, 3-(N-allylamino)propyl,N-(2-aminoethyl)-3-aminopropyl, N-(2-aminoethyl)-3-aminoisobutyl,p-aminophenyl, 2-ethylpyridine, and 3-propylpyrrole groups; epoxyalkylgroups such as 3-glycidoxypropyl, 2-(3,4,-epoxycyclohexyl)ethyl, and5,6-epoxyhexyl groups; ester functional groups such as acetoxymethyl andbenzoyloxypropyl groups; hydroxy functional groups such as hydroxy and2-hydroxyethyl groups; isocyanate and masked isocyanate functionalgroups such as 3-isocyanatopropyl, tris-3-propylisocyanurate,propyl-t-butylcarbamate, and propylethylcarbamate groups; aldehydefunctional groups such as undecanal and butyraldehyde groups; anhydridefunctional groups such as 3-propyl succinic anhydride and 3-propylmaleic anhydride groups; carboxylic acid functional groups such as3-carboxypropyl and 2-carboxyethyl groups; carbazole groups such as3-(N-carbazolyl)propyl; arylamino-functional groups such as4-(N,N-diphenylamino)phenyl-3-propyl; and metal salts of carboxylicacids such as the zinc, sodium, or potassium salts of 3-carboxypropyland 2-carboxyethyl.

The R² group is exemplified by alkenyl groups such as vinyl, allyl, andbutenyl groups; alkynyl groups such as ethynyl and propynyl groups; andacrylic functional groups such as acryloxypropyl and methacryloxypropylgroups. As noted, the R³ groups can be the same as the R¹ groups. The R⁴group is exemplified by alkenyl groups such as vinyl, allyl, and butenylgroups; alkynyl groups such as ethynyl and propynyl groups;alkenyloxypoly(oxyalkyene) groups such as allyloxy(polyoxyethylene),allyloxypoly(oxypropylene), andallyloxy-poly(oxypropylene)-co-poly(oxyethylene) groups; and acrylicfunctional groups such as acryloxymethyl, acryloxypropyl,methacryloxymethyl, and methacryloxypropyl groups.

Some representative organopolysiloxane fluids suitable for use in theradical curable component include α,ω-methacryloxypropyl-dimethylsilylterminated polydimethylsiloxanes; α,ω-methacryloxymethyl-dimethylsilylterminated polydimethylsiloxanes; α,ω-acryloxypropyl-dimethylsilylterminated polydimethylsiloxanes; α,ω-acryloxymethyl-dimethylsilylterminated polydimethylsiloxanes; pendant acrylate functional polymersand methacrylate functional polymers such aspoly(acryloxypropyl-methylsiloxy)-polydimethylsiloxane copolymers andpoly(methacryloxypropyl-methylsiloxy)-polydimethylsiloxane copolymers;and telechelic polydimethylsiloxanes having multiple acrylate functionalgroups or methacrylate functional groups such as compositions formed viaMichael addition of multi-acrylate monomers or multi-methacrylatemonomers to amine terminated polydimethylsiloxanes. Such functionalizingreactions can be carried out a priori or in-situ.

For the radical curable component, it may be desirable to use a mixtureof organopolysiloxane fluids differing in their degree of functionalityand/or the nature of the free radical polymerizable group. For example,a much faster crosslinking efficiency and a reduced sol content can beobtained by using a tetra-functional telechelic polydimethylsiloxaneprepared by the Michael addition reaction ofN-(methyl)isobutyl-dimethylsilyl terminated polydimethylsiloxane withtwo molar equivalents of trimethylolpropane tri-acrylate as the radicalcurable component, relative to di-functionalmethacryloxypropyl-dimethylsilyl terminated polydimethylsiloxanes havinga similar degree of polymerization (DP). However, the lattercompositions also produce lower modulus elastomeric patterns. Hence,combinations of organopolysiloxane fluids having differing structuresmay be quite useful. Methods for preparing such organopolysiloxanefluids are known and include the hydrolysis and condensation of thecorresponding organohalosilanes or the equilibration of cyclicpolydiorganosiloxanes.

The radical curable component can include an organosiloxane resinincluding MQ resins containing R⁵ ₃SiO_(1/2) units and SiO_(4/2) units;TD resins containing R⁵SiO_(3/2) units and R⁵ ₂SiO_(2/2) units; MTresins containing R⁵ ₃SiO_(1/2) units and R⁵SiO_(3/2) units; MTD resinscontaining R⁵ ₃SiO_(1/2) units, R⁵SiO_(3/2) units, and R⁵ ₂SiO_(2/2)units; or combinations thereof. Each R⁵ group in these organosiloxaneresins represents a monovalent organic group. The monovalent organicgroup R⁵ can have 1-20 carbon atoms, preferably 1-10 carbon atoms.

Some examples of suitable monovalent organic groups representative ofthe R⁵ group include acrylate functional groups such as acryloxyalkylgroups; methacrylate functional groups such as methacryloxyalkyl groups;cyano functional groups; and monovalent hydrocarbon groups. Monovalenthydrocarbon groups include alkyl groups such as methyl, ethyl, propyl,pentyl, octyl, undecyl, and octadecyl groups; cycloalkyl groups such ascyclohexyl groups; alkenyl groups such as vinyl, allyl, butenyl, andhexenyl groups; alkynyl groups such as ethynyl, propynyl, and butynylgroups; aryl groups such as phenyl, tolyl, xylyl, benzyl, and2-phenylethyl groups; halogenated hydrocarbon groups such as3,3,3-trifluoropropyl, 3-chloropropyl, dichlorophenyl, and6,6,6,5,5,4,4,3,3-nonafluorohexyl groups; and cyano-functional groupsincluding cyanoalkyl groups such as cyanoethyl and cyanopropyl groups.

The R⁵ group can also comprise an alkyloxypoly(oxyalkyene) group such aspropyloxy(polyoxyethylene), propyloxypoly(oxypropylene) andpropyloxy-poly(oxypropylene)-co-poly(oxyethylene) groups; halogensubstituted alkyloxypoly(oxyalkyene) groups such asperfluoropropyloxy(polyoxyethylene),perfluoropropyloxypoly(oxypropylene) andperfluoropropyloxy-poly(oxypropylene)-co-poly(oxyethylene) groups;alkenyloxypoly(oxyalkyene) groups such as allyloxypoly(oxyethylene),allyloxypoly(oxypropylene) andallyloxy-poly(oxypropylene)-co-poly(oxyethylene) groups; alkoxy groupssuch as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy andethylhexyloxy groups; aminoalkyl groups such as 3-aminopropyl,6-aminohexyl, 11-aminoundecyl, 3-(N-allylamino)propyl,N-(2-aminoethyl)-3-aminopropyl, N-(2-aminoethyl)-3-aminoisobutyl,p-aminophenyl, 2-ethylpyridine, and 3-propylpyrrole groups; hinderedaminoalkyl groups such as tetramethylpiperidinyl oxypropyl groups;epoxyalkyl groups such as 3-glycidoxypropyl,2-(3,4,-epoxycyclohexyl)ethyl, and 5,6-epoxyhexyl groups; esterfunctional groups such as acetoxymethyl and benzoyloxypropyl groups;hydroxy functional groups such as hydroxy and 2-hydroxyethyl groups;isocyanate and masked isocyanate functional groups such as3-isocyanatopropyl, tris-3-propylisocyanurate, propyl-t-butylcarbamate,and propylethylcarbamate groups; aldehyde functional groups such asundecanal and butyraldehyde groups; anhydride functional groups such as3-propyl succinic anhydride and 3-propyl maleic anhydride groups;carboxylic acid functional groups such as 3-carboxypropyl,2-carboxyethyl, and 10-carboxydecyl groups; carbazole groups such as3-(N-carbazolyl)propyl; arylamino-functional groups such as4-(N,N-diphenylamino)phenyl-3-propyl; and metal salts of carboxylicacids such as zinc, sodium, and potassium salts of 3-carboxypropyl and2-carboxyethyl.

The organosiloxane resin can contain an average of 1-40 mole percent ofradical polymerizable groups such as unsaturated organic groups. Theunsaturated organic groups may be alkenyl groups, alkynyl groups,acrylate-functional groups, methacrylate-functional groups, or acombination of such groups. The mole percent of unsaturated organicgroups in the organosiloxane resin is considered herein to be the ratioof (i) the number of moles of unsaturated groups containing siloxaneunits in the resin, to (ii) the total number of moles of siloxane unitsin the resin, times a factor of 100. Some specific examples of suitableorganosiloxane resins that are useful as the radical curable componentare M^(Methacryloxymethyl)Q resins, M^(Methacryloxypropyl)Q resins,MT^(Methacryloxymethyl)T resins, MT^(Methacryloxypropyl)T resins,MDT^(Methacryloxymethyl)T^(Phenyl)T resins,MDT^(Methacryloxypropyl)T^(Phenyl)T resins, M^(Vinyl)T^(Phenyl) resins,TT^(Methacryloxymethyl) resins, TT^(Methacryloxypropyl) resins,T^(Phenyl)T^(Methacryloxymethyl) resins,T^(Phenyl)T^(Methacryloxypropyl) resins,TT^(Phenyl)T^(Methacryloxymethyl) resins, andTT^(Phenyl)T^(Methacryloxypropyl) resins, where M, D, T, and Q have thesame meanings as defined above.

Methods of preparing such organosiloxane resins are known includingresins made by treating a resin copolymer produced by a silica hydrosolcapping process, with an alkenyl containing endblocking reagent, asdescribed in U.S. Pat. No. 2,676,182, which is expressly incorporatedherein by reference relative to the aforementioned methods of producingorganosiloxane resins. This method involves reacting a silica hydrosolunder acidic conditions with a hydrolyzable triorganosilane such astrimethylchlorosilane, a siloxane such as hexamethyldisiloxane, or amixture thereof, followed by recovery of a copolymer having M and Qunits. The copolymer typically contains about 2-5 percent by weight ofhydroxyl groups. Organosiloxane resins containing less than about 2percent by weight of silicon bonded hydroxyl groups may then be preparedby reacting the copolymer with an endblocking agent containingunsaturated organic groups, and with an endblocking agent free ofaliphatic unsaturation, in an amount sufficient to provide about 3 toabout 30 mole percent of unsaturated organic groups in the product. Somesuitable endblocking agents include silazanes, siloxanes, and silanes;and preferred endblocking agents are described in U.S. Pat. Nos.4,584,355, 4,585,836, and 4,591,622, which are each expresslyincorporated herein by reference relative to the aforementionedendblocking agents. A single endblocking agent or a mixture ofendblocking agents may be used to prepare such organosiloxane resins.

Another type of organosilicon compound that can be used in the radicalcurable component is a composition formed by copolymerizing an organiccompound, having a polymeric backbone, with an organopolysiloxane, wherean average of at least one free radical polymerizable group isincorporated per molecule. Some suitable organic compounds includehydrocarbon based polymers such as polyisobutylene, polybutadienes, andpolyisoprenes; polyolefins such as polyethylene, polypropylene andpolyethylene polypropylene copolymers; polystyrenes; styrene butadiene;and acrylonitrile butadiene styrene; polyacrylates; polyethers such aspolyethylene oxide or polypropylene oxide; polyesters such aspolyethylene terephthalate or polybutylene terephthalate; polyamides;polycarbonates; polyimides; polyureas; polymethacrylates;polythiophenes; polypyrroles; polyanilines; polyacetylene; polyphenylenevinylene; polyvinylpyridenes; and partially fluorinated orperfluorinated polymers such as polytetrafluoroethylene; fluorinatedrubbers; terminally unsaturated hydrocarbons; olefins; and polyolefins.The organic compound can be a copolymer of any of these polymers,including polymers containing multiple organic functionality, multipleorganopolysiloxane functionality, or combinations of organopolysiloxanesand organic compounds. The copolymeric structures can vary in thearrangement of repeating units from random, grafted, to being blocky innature.

The radical curable component, in addition to bearing on average atleast one radical polymerizable group, may have a physical transitiontemperature, bear an organo functional group with a physical transitiontemperature, or upon polymerization or crosslinking may form particlesthat have a physical transition temperature, i.e., glass transition ormelting transition, such that the composition undergoes changes markedby a softening or non-linear reduction in its viscosity on reachingcertain temperatures under the conditions of use. Such materials areparticularly useful for encapsulation of actives that are released bythe introduction of heat. For example, an organopolysiloxane-basedversion of the radical curable component may be an organo functionalsilicone wax. The wax can be an uncrosslinked organo functional siliconewax, a crosslinked organo functional silicone wax, or a combination ofwaxes. Such silicone waxes are commercially available and are describedin U.S. Pat. No. 6,620,515, which is expressly incorporated herein byreference relative to the silicone waxes. When the organo functionalsilicone wax bears at least one free radical polymerizable group such asan acrylate or methacrylate group, the wax is useful to impart phasechanges when used as the radical curable component. The radical curablecomponent can also comprise a mixture of any of the organic compounds,organosilicon compounds, and/or organopolysiloxane compounds describedabove.

Some representative and preferred examples of the radical curablecomponent include acrylic and methacrylic organic monomers,multifunctional monomers and macromonomers. Also, (meth)acrylicfunctional siloxane linear polymers, resins, and copolymers may also beincluded as the radical curable component, and are particularly usefulfor tuning properties such as surface energy, modulus, thermalstability, moisture resistance, and hydrophobic balance.

While the specific radical curable compounds set forth above typicallymake up about 100% by weight of the radical curable component, it is tobe appreciated that other compounds, such as impurities and othercompounds known in the art to be commonly present with the radicalcurable compounds may also be present in the radical curable componentsuch that less than 100% by weight of the radical curable component isthe radical curable compounds.

In some cases, the radical curable component may also function as thedecomplexing component. For example, both acrylic acid and methacrylicacid are capable of reacting with an amine in the organoborane-aminecomplex, and both are also radical curable. Thus, the method, article,and composition of this invention may include the radical curablecomponent serving as both a radical curable component and as thedecomplexing component simultaneously.

Development of the radical curable component may occur upon exposure ofthe composition including the organoborane initiator, the radicalcurable component, and optionally the decomplexing component, to (iv) adeveloping medium. The developing medium can be a liquid, a gas, asolid, or a mixture thereof. The developing medium is typically a mediumthat includes oxygen. Oxygen may be present in any diluted, dissolved,or pure form, and may be implicitly present in the form of atmosphericair, or explicitly introduced to the composition on the substrate orinto the processing environment surrounding the composition on thesubstrate. Although it is not typically necessary, it may be desirablein some cases to increase, reduce, or eliminate naturally occurringoxygen content in either the composition, in the developing medium, orin the individual organoborane initiator, decomplexing component, and/orradical curable component, by controlling pressure and/or quality of theatmosphere in which the components are stored and in which the method ofthe invention is carried out. Explicit control of the oxygen content maybe carried out by any number of known methods, including controlling thepressures of various types of gases including oxygen, compressed air,oxygen-enriched air, argon, nitrogen, helium and, and/or the inclusionof an oxygen scavenging, oxygen storing, oxygen generating, and/oroxygen releasing substance. Oxygen, for purposes herein, includes allisotopes of oxygen. Oxygen may be introduced as a gas, a liquid, or asolid, but preferably is introduced in the gas phase. Most preferably,the source of oxygen is air.

One or more optional components can be included in the composition. Suchoptional components may be selected from the group of coloringcomponents such as dyes and pigments; surfactants; water; wettingagents; solvents including common organic aqueous solvents, ionicliquids, and supercritical fluids; diluents; plasticizers; polymers;oligomers; rheology modifiers; adhesion promoters; crosslinking agents;combinations of polymers, crosslinking agents, and catalysts useful forproviding a secondary cure of the pattern; polymers capable ofextending, softening, reinforcing, toughening, modifying viscosity, orreducing volatility when mixed into the composition; extending andreinforcing fillers; conductive fillers, spacers; dopants; quantum dotssuch as nanoparticles of cadmium selenide; co-monomers such as organicacrylates and organic methacrylates; UV stabilizers; aziridinestabilizers; void reducing agents; cure modifiers such as hydroquinoneand hindered amines; free radical initiators such as organic peroxidesand ozonides; acid acceptors; antioxidants; oxygen scavengers; oxygensponges; oxygen releasing agents; oxygen generators; heat stabilizers;flame retardants; silylating agents; foam stabilizers; fluxing agents;desiccants; and combinations thereof. The optional components may beintroduced into the composition through any of the other components thatform the composition, such as through the organoborane initiator, theradical curable component, and/or the decomplexing component, theoptional developing medium, or through inclusion in a combination of theaforementioned components.

In some cases, it may be desirable to attach the decomplexing componentto solid particles which may be any of the solid particles describedabove. Alternatively, the solid particles may have properties such aselectrical conductivity or thermal conductivity, or ferroelectricproperties, that can render the resulting pattern more useful forsubsequent applications. Attachment of the decomplexing agent, e.g.organonitrogen reactive compounds, can be accomplished by a number ofknown surface treatments either in-situ or a priori. Some surfacetreatment methods include, for example, pre-treating solid particlessuch as ground or precipitated silica, calcium carbonate, carbon black,carbon nanoparticles, silicon nanoparticles, barium sulfate, titaniumdioxide, aluminum oxide, boron nitride, silver, gold, platinum,palladium, and alloys thereof; or a base metal such as nickel, aluminum,copper, and steel; with a condensation reactive compound. This isfollowed by reaction of the pre-treated solid particles with a compoundhaving organonitrogen or amine reactive groups, or by the directtreatment of the pre-treated solid particles using organonitrogen oramine reactive compounds that have hydrolyzable moieties.

Some examples of condensation reactive compounds that can be used forattachment include isocyanatomethyltriethoxysilane,isocyanatopropyltriethoxysilane, isocyanatomethyltrimethoxysilane,isocyanatopropyltrimethoxysilane, triethoxysilylundecanal,glycidoxymethyltrimethoxysilane, glycidoxypropyltrimethoxysilane,3-(triethoxysilyl)methylsuccinic anhydride,3-(triethoxysilyl)propylsuccinic anhydride, and2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane. Attachment of thedecomplexing component to the solid particles can also be accomplishedby mixing an acid functional compound with fillers having theappropriate surface functionality, under conditions conducive toformation of an acid base complex, a hydrogen bonded complex, or an acidsalt.

Some particulate fillers are commercially available that are pre-treatedwith surface treating agents referred to as lubricants, or that can beobtained with impurities that contain amine reactive groups, such ascarboxylic acid. In this way, the decomplexing component may include theorganonitrogen or amine reactive compound and an optional component thatcan be delivered together in the form of a treated filler. The advantageobtained in this instance is that a reaction between anorganoborane-amine complex, as the organoborane initiator, and the aminereactive groups in the filler can help remove the lubricant from thesurface of the filler particles. The lubricant may be necessary forstability of the particle in concentrated form, but it can interferewith the intended function of the filler. The reaction of anorganoborane-amine complex, as the organoborane initiator, and theamine-reactive lubricant can effectively remove the lubricant from theparticle surface, thereby activating the particle. A typical example isa fatty-acid treated silver filler particle, wherein the fatty acidlubricant interferes with particle-to-particle contact, which may beneeded for establishing electrical conductivity in a final form.

It may also be advantageous, for the sake of stability, to use acombination of fillers containing organonitrogen or amine reactivegroups and fillers that are inert with respect to organonitrogencompounds and/or amines. For example, when the organoborane initiatorand the decomplexing component are maintained in separate solutions, thefiller that is inert with respect to organonitrogen compounds and/oramines can be combined with the organoborane initiator, while the fillerbearing organonitrogen or amine reactive groups can be packaged in aseparate container from the organoborane initiator. In that case, theradical curable component can be included with any part of theformulation, or with more than one part. Alternatively, the decomplexingcomponent can be introduced under conditions that allow it to bedelivered in the gas phase to a reaction vessel containing the remainderof the composition.

As first introduced above, some representative and preferred examples oforganonitrogen or amine reactive groups include carboxylic acid,anhydride, isocyanate, aldehydes, and epoxies. Blocked isocyanates maybe useful in cases where instead of ambient polymerization, it isdesirable to use heat to initiate polymerization rapidly.

It should be noted that the organoborane initiator, the decomplexingcomponent, the radical curable component, and the developing medium, canbe deposited onto the substrate in any combination. Further, theorganoborane initiator, the decomplexing component, the radical curablecomponent, and the developing medium can be deposited onto the substratein any manner that is capable of forming the gradient pattern. Forexample, any number of well established methods, including pipetting,manual writing, typewriting, gravure printing, engraving, thermography,rubber stamping, screen printing, pad printing, stencil printing, orinkjet printing may be used. Typically, the organoborane initiator, theradical curable component, and/or the decomplexing component aredeposited by printing onto the substrate, optionally in the presence ofthe developing medium. The printing may be further defined as digitalprinting, one example of which is ink-jet printing. As withmicrolithographic methods, the composition may be developed or cured toyield either a positive or negative tone image for subsequentprocessing.

Preferably, the decomplexing component and the radical curable componentare not intimately mixed together in the presence of the developingmedium prior to developing. For example, in one embodiment, at least oneof the organoborane initiator and the radical curable component isdeposited separate from the other. In another embodiment, at least oneof the organoborane initiator, the decomplexing component, and theradical curable component is deposited separate from the others. It iscontemplated that the organoborane initiator, the radical curablecomponent, and optionally the decomplexing component may be deposited onthe substrate simultaneously in space and/or time or separately from oneother in space and/or time. In one embodiment, the organoboraneinitiator, the radical curable component, and optionally thedecomplexing component are deposited separately from one another but atthe same time, e.g. in different streams. Alternatively, theorganoborane initiator, the radical curable component, and optionallythe decomplexing component may be deposited separately from one anotherat different times but on the same portion of the substrate. The methodmay be carried out by depositing the organoborane initiator onto thesubstrate before the decomplexing component and/or radical curablecomponent. Alternatively, the method may be carried out by depositingthe radical curable component and the organoborane initiator, and thendepositing the decomplexing component onto the substrate. Alternativelystill, the method may be carried out by depositing the decomplexingcomponent onto the substrate before the organoborane initiator and theradical curable component. In another embodiment, the composition isfurther defined as including a first mixture including the organoboraneinitiator and a first radical curable component (e.g. first radicalcurable monomer) and a second mixture including a second radical curablecomponent (e.g. a second radical curable monomer) and the decomplexingcomponent while the step of depositing is further defined as depositingthe first and second mixtures onto the substrate. The first and secondmixtures may be deposited on the substrate simultaneously or separatelyin time and/or space.

The composition may be deposited onto the substrate either post-hoc, viaa surface functionalization step such as selective priming, via UV orcorona treatment to create amine-reactive, or in-situ via a selfassembly process during processing of the substrate. Here, thedecomplexing component may be present in the substrate either inherentlyor as an additive. Alternatively still, the method may be carried out bydepositing the radical curable component onto the substrate before theorganoborane initiator and/or the decomplexing component.

When at least one of the organoborane initiator, the radical curablecomponent, and/or the decomplexing component are deposited separate fromthe other of the components, one or more of these are generally providedin separate solutions. For example, in one embodiment, a first solutionincluding the radical curable component and the organoborane initiator,and a second solution including the decomplexing component are provided.Both solutions are typically air stable, but after the first solution isdeposited onto the substrate in the pattern, the pattern developsrapidly to solidify the pattern when the pattern is exposed to thesecond solution in ambient conditions. In another embodiment, theorganoborane initiator or the decomplexing component, or both, can beencapsulated or delivered in separate phases. This can be accomplishedby introducing one or both of the organoborane initiator and thedecomplexing component in a solid form that prevents intimate mixing ofthose components. Development of the pattern can be activated by (a)heating it above the softening temperature of the solid phase componentor encapsulant, or (b) by the introduction of a solubilizing agent forthe solid phase that allows mixing of the organoborane initiator and thedecomplexing component. In yet another method, a heterophase liquidsolution such as an emulsion is used, in which the organoboraneinitiator and the decomplexing component are present together but inseparate liquid phases. The pattern may then be developed physicallysuch as by shear or heating to break the emulsion, or chemically byexposing the pattern to a compound that causes the organoboraneinitiator and the decomplexing component to contact each other andreact. The organoborane initiator and the decomplexing component canalso be combined in a single container without significant developmentby packaging the two components where mixing conditions are anaerobic.In this case, pattern development can be initiated by introduction ofoxygen to the composition.

In the embodiments where the organoborane initiator, the radical curablecomponent, and/or the decomplexing component are provided in separatesolutions, the organoborane initiator and the decomplexing component aretypically isolated from one another until after the pattern has beenformed on the substrate with one of the solutions. The pattern is thentypically developed in place upon exposure of the organoborane initiatorand the decomplexing component to each other in the presence of thedeveloping medium, without the need for heating or radiation. However,heating or radiation may still be used in this invention.

The gradient pattern is formed on the substrate by depositing thecomposition on the substrate wherein at least one of the organoboraneinitiator and the radical curable component is deposited onto thesubstrate in the form of the gradient pattern. In one embodiment, thegradient pattern is formed on the substrate by depositing thedecomplexing component, either in combination or apart from at least oneof the organoborane initiator and the radical curable component, ontothe substrate in the form of the gradient pattern. The remainingcomponents, if any, may be deposited either simultaneously orseparately, and may be deposited in different patterns. The compositionmay then developed by exposure to either a chemical agent such as ade-emulsifier or solvent, or to physical processes such as shearing,irradiation, heating, cooling, pressurization, or depressurization, tocause the organoborane initiator and the decomplexing component to comeinto contact with one another in the presence of the developing medium.For example, where the organoborane initiator, the radical curablecomponent, and/or the decomplexing component are provided in separatesolutions, the first solution including the organoborane initiator andthe radical curable component may be deposited onto the substrate toform the gradient pattern. The method of deposition may be as simple ashand-lettering with a brush or a fine-tipped applicator, or for finerresolution, it can be transferred via a rubber stamp wetted with theink, stencil or screen printed, or printed out of an inkjet printer witha cartridge filled with the first solution. The resulting pattern maythen be heated to activate the organoborane initiator or be developed byexposure of the substrate including the pattern formed by the firstsolution to an environment rich in the decomplexing component, such asby dipping in a bath of the decomplexing component, by passing thesubstrate through a chamber in which the vapor space contains thedecomplexing component, by passing the substrate through a fluidized bedof solid particles bearing the decomplexing component, or byoverprinting the pattern with an inkjet printer having a cartridgefilled with a solution containing the decomplexing component, in thepresence of the developing medium, or followed by exposure to thedeveloping medium. In such multi-package systems, the method of exposingthe substrate including the pattern formed thereon to the secondsolution may be done in several ways such as via immersion of the entiresubstrate, by dipping in a bath, exposing to a vapor chamber, orselectively exposing the pattern such as by over-spraying the patternfrom another inkjet cartridge containing the second solution. It may beconvenient to use an inkjet printing cartridge with separate reservoirs,as exemplified by a multi-colored inkjet cartridge, or two separatecartridges on a single printer carriage, to separately store the firstsolution, the second solution, and/or the developing medium, and toallow application and development of the pattern, simply by mixing thecomponents in the process of inkjet printing.

As is known in the art, an inkjet printer can dispense droplets from aprinthead with lateral spacing between rows of the droplets defined by apitch of a nozzle plate. To prepare a continuous film, an appropriatesubstrate may be selected to allow the droplets to wet the substrate andspread. Alternatively, multiple passes over a single area of a substratecan be made using the inkjet printer while offsetting the printhead(e.g. by 50 microns) per pass. Alternatively, gradient patterns can beprinted wherein a density of deposited components can vary across thesubstrate.

Pre-attachment of the organoborane initiator to monolithic, i.e.,continuous rather than particulate, surfaces can be performed in theembodiment of the invention where the organoborane initiator isdeposited onto the substrate, followed by deposition of the decomplexingcomponent. For example, an organoborane initiator having an alkoxysilylgroup such as 3-aminopropyltriethoxysilane, complexed with an equimolaramount of triethylborane, may be pre-attached to a substrate such asgold or glass by relying on the strong interaction or reactivity betweenthe substrate and the organoborane initiator. The pre-attachment may beperformed selectively in the gradient pattern, or as a general treatmentor priming provided at least one of the remaining components of thecomposition is deposited in the desired pattern. As described above, theradical curable component can be deposited together with either theorganoborane initiator or the decomplexing component, or both in thisembodiment. To control the pattern formation and adhesion on thesubstrate, it may be desirable to use a combination of low and highsurface energy organoborane initiators in the composition.

Pre-attachment of the decomplexing component to monolithic, i.e.,continuous rather than particulate, substrates can be performed in theembodiment of the invention where the decomplexing component isdeposited onto the substrate, followed by deposition of the organoboraneinitiator. For example, an organonitrogen- or amine-reactive compoundhaving an alkoxysilyl group such as 3-isocyanopropyl trimethoxysilanemay be pre-attached to a substrate such as gold or glass, by relying onthe strong interaction or reactivity between the substrate and theorganonitrogen- or amine-reactive compound. The pre-attachment may becarried out selectively in the desired pattern, or as a generaltreatment or priming provided at least one of the remaining componentsof the composition is deposited in the desired pattern. As describedabove, the radical curable component can be deposited together witheither the organoborane initiator or the decomplexing component, or bothin this embodiment. To control the pattern formation and adhesion on thesubstrate, it may be desirable to use a combination of low and highsurface energy organonitrogen-reactive compounds in the composition.

The organoborane initiator, the radical curable component, and/or thedecomplexing component may be deposited simultaneously. As describedabove, the terminology “simultaneously”, may include the deposition ofthe organoborane initiator, the radical curable component, and/or thedecomplexing component at the same time, in the same place, or at thesame time in the same place. In this embodiment, the organoboraneinitiator, the radical curable component, and/or the decomplexingcomponent may exist in a single solution and may be deposited togetheronto the substrate. The organoborane initiator and the decomplexingcomponent are typically isolated from one another by being present inseparate phases of a multiphase system such as an emulsion, or viaencapsulation of at least one of the organoborane initiator or thedecomplexing component. Here, because the organoborane initiator and thedecomplexing component are in separate phases, it is not necessary tostore and process the composition in the absence of the developingmedium, such as oxygen. The composition may be deposited onto thesubstrate, then developed either by exposure to the developing mediumincluding a chemical agent such as a de-emulsifier or solvent, or byexposure to a physical process such as shearing, irradiation, heating,cooling, pressurization, or depressurization, when oxygen is used as thedeveloping medium, to cause the organoborane initiator and thedecomplexing component to come into intimate contact with one another inthe presence of the oxygen. Alternatively, the organoborane initiator,the radical curable component, and/or the decomplexing component may bekept separate up until deposition, as set forth above when thecomponents are separately deposited onto the substrate.

In the embodiment, the organoborane initiator, the decomplexingcomponent, and the radical curable component are combined together toform the composition that is deposited in the gradient pattern onto thesubstrate, all in an environment free of the developing medium, e.g. inan oxygen free atmosphere. Blankets of gases such as nitrogen, carbondioxide, or noble gases may be used. The gradient pattern is thendeveloped by exposure of the composition to an environment containingthe developing medium, such as air including oxygen. In anotherembodiment, the organoborane initiator and the decomplexing componentare isolated from one another by being present in separate phases of amultiphase system such as an emulsion or via encapsulation of at leastone of the organoborane initiator and the decomplexing component, asdescribed above.

It is to be appreciated that the organoborane initiator, the radicalcurable component, and/or the decomplexing component may be deposited inthe presence of oxygen as the developing medium to develop the gradientpattern on the substrate. Typically, oxygen is inherently present in theform of air, but it may be deliberately excluded from or introduced tothe composition, the developing medium, or a processing environmentsurrounding the composition on the substrate. For example, an inert gaspurge may be used to accelerate curing. In some cases, some of theorganoborane initiator, the radical curable component, and/or thedecomplexing component may be deposited in the absence of the developingmedium, while other components may be deposited in the presence of thedeveloping medium. For example, when one or more of the organoboraneinitiator, the radical curable component, and/or the decomplexingcomponent are deposited before the others, the first to be deposited maybe deposited in the absence of the developing medium, while the rest maybe deposited in the presence of the developing medium. Alternatively,when the organoborane initiator, the radical curable component, and/orthe decomplexing component are deposited simultaneously, theorganoborane initiator, the radical curable component, and/or thedecomplexing component may be deposited in the absence of the developingmedium, such as oxygen. Once on the substrate, the composition may thenbe exposed to the developing medium including oxygen, such as air, todevelop or cure the composition on the substrate in the desired pattern,i.e., in the form of the gradient pattern.

Development typically occurs upon mixing of the organoborane initiator,the radical curable component, and the decomplexing component with thedeveloping medium. The deposition of the organoborane initiator, theradical curable component, and/or the decomplexing component onto thesubstrate may be physical, i.e., through adsorption, or it may involvethe formation of covalent bonds with the surface, i.e., throughgrafting. As opposed to purely physical patterning methods, thecomposition of the present invention undergoes an increase in averagemolecular weight via free radical polymerization during development,such as from a monomeric or macromonomeric fluid to a polymer film. Inthis respect, development of the composition of the present invention issimilar to lithographic techniques based upon photopolymerization, butit does not require photoinitiators or a light source.

Because the organoborane initiator, the radical curable component,and/or the decomplexing component of the composition may be distributedin various manners in the several embodiments, their relative amountscan vary widely. For example, when the organoborane initiator, theradical curable component, and/or the decomplexing component areincluded in separate solutions, the developing medium may contain alarge excess of one particular compound to allow multiple samples of apattern, including the remaining compounds of the composition and thesubstrate, to be developed by passing through the developing medium in acontinuous or semi-continuous process. However, the amount of thedeveloping medium needed to develop just one pattern may be hundreds oftimes smaller. The organoborane initiator is typically deposited in anamount of from about 0.1 to about 50 parts by weight, more typicallyfrom about 0.5 to about 30 parts by weight, per 100 parts by weight ofthe composition. The decomplexing component is typically deposited in anamount of from about 0.1 to about 50 parts by weight, more typicallyfrom about 0.2 to about 40 parts by weight, per 100 parts by weight ofthe composition. The radical curable component is typically deposited inan amount of from about 0.1 to about 99.9 parts by weight, moretypically from about 1 to 99 parts by weight, per 100 parts by weight ofthe composition. The developing medium typically includes oxygen in anamount of from 0.0001 to infinite parts by weight, per 100 parts byweight of the composition. The optional components may be used in anamount of from 0 to about 99 parts by weight, more typically from about0.1 to about 80 parts by weight, per 100 parts by weight of thecomposition. In any case, the amounts may be scaled to accommodate anyconvenient mass or volume. The range of oxygen is essentially unlimited,since oxygen can be present in any environment such as air.

In one embodiment, the development rate of the composition can becontrolled by introducing additional amines to increase a molar ratio ofamine groups to boron atoms in the composition. The effective amount ofthe additional amine to be added depends on the amine:boron ratio usedin the organoborane initiator. It is preferred that the overallamine:boron ratio remains sufficiently low, however, to permitdevelopment to occur. A suitable amine:boron ratio is typically lessthan about 10:1, preferably less than about 4:1. When the decomplexingcomponent is already present in the composition prior to deposition,i.e., when residual carboxylic acid is present on optional fillerparticles, higher levels of amine compounds are typically added toneutralize or partially neutralize the amine reactive groups in thedecomplexing component to reduce the development rate. The additionalamine may contain monofunctional or multifunctional amine groups, and itcan be a primary amine, a secondary amine, and/or a tertiary amine. Ifdesired, the amine can contain radical polymerizable groups or anotherfunctional group such as a hydrolyzable group. The additional amine canbe monomeric, oligomeric, or polymeric in nature. Amine groups in theadditional amine may be borne on an organic, organosilicon, ororganopolysiloxane compound.

The substrate on which the composition is deposited is not limited.Examples of suitable substrates include glass surfaces, metal surfaces,quartz surfaces, ceramic surfaces, silicon surfaces, organic surfaces,rigid polymeric surfaces, flexible elastomeric surfaces, or compositesurfaces thereof. The substrates can be multi-layered substrates, suchas substrates used in printed circuit boards, in which improved adhesionis desired between the curable pattern and the substrate or substratesof the composite article. Some specific examples of substrates includesilicon, silica, alumina, cerium oxide, glass, gold, platinum,palladium, rhodium, silver, steel, stainless steel, anodized steel,aluminum, anodized aluminum, cast aluminum, titanium, nickel, copper,brass, and oxides thereof; circuit boards; polyethylene, polypropylene,polystyrene, syndiotatic-polystyrene, polybutylene terephthalate,polycarbonate, polyphthalamide; polyphenylene sulfide; epoxy resins;bis-maleimide triazine resins; fluoropolymers such aspolytetrafluoroethylene, natural rubber, latex rubbers, silicone,fluorosilicone, pressure sensitive tapes and adhesives; and cellulosicpolymers such as wood, paper, and other natural polymers.

The substrate may also be a frozen liquid, such as ice or dry ice, tocreate freely standing templates or decals that may be transferred toanother substrate by allowing the substrate to melt after the patternhas been created. The substrate may also be a liquid surface, such aswater, heptane, silicone oil, or mercury, provided the compositionretains the desired features of the pattern until development iscomplete. In cases where it is desirable to form freely standingpatterns such as for transfer as decals, one may deposit the compositiononto the surface of substrates that are meltable or sublimable solidssuch as ice or dry ice, or liquid substrate surfaces such as water, oil,or liquid organopolysiloxane, provided the surface does not dissolve thedesired pattern, or otherwise impair development of the desired pattern.In these instances, it may be convenient to deposit the decomplexingcomponent by imbibing it into the substrate, as exemplified bydissolving of acrylic acid or polyacrylic acid into water or ice.Preferably, the composition does not spread or dissolve in the liquidsurface when applied to the liquid surface.

The resulting properties of the developed or cured composition are notparticularly limited. For example, the composition can be formulated toyield a gradient pattern that may be rigid, flexible, transparent,translucent, opaque, elastomeric, amorphous, semi-crystalline, liquidcrystalline, thermoplastic, thermosetting, thermally or electricallyinsulating, thermally or electrically semi-conductive, or thermally orelectrically conductive. Formation of the gradient pattern enablescharacterization of the composition and testing of the resultingproperties of the developed or cured composition.

After the composition on the substrate is developed or cured, i.e.,after the organoborane initiator, decomplexing component, and/or radicalcurable component react, the developed composition may be analyzed. Thedeveloped composition may be analyzed to determine any range of desiredchemical, surface and physical properties. For example, properties suchas extent of cure, hardness, adhesion, abrasion resistance, glasstransition temperature, melting temperature, miscibility, transparency,roughness, surface elemental, molecular or functional groupconcentration may be analyzed via a range of techniques. Non-limitingexamples of such techniques include various spectroscopies includinginfrared spectroscopy, attenuated total reflectance infraredspectroscopy, Raman spectroscopy, infrared microscopy, UV-Visspectroscopy, and x-ray photoelectron spectroscopy, microscopies such asoptical, scanning electron, and transmission electron microscopy,adhesion tests, nanonindentation tests, microindentation tests,digestion techniques, chemical titration tests, tape-pull off tests,contact mechanical adhesion tests, thermal shock tests, AFM calorimetry,colorimetry, and known methods for testing electrical and thermalconductance, resistance, and calorimetry. Alternatively, the developedcomposition may be analyzed using manual smearing and/or visualinspection. Manual smearing includes smearing or smudging thecomposition with a gloved finger to test whether the composition isdeveloped/cured. The composition is typically analyzed at apredetermined location of the gradient pattern, where the relativeamounts of the components are known. Additionally, the instant inventionmay include any or all of the disclosure of International ApplicationNumber: PCT/US2006/030192, which in its entirety, is incorporated hereinby reference.

The following examples are meant to illustrate, and not to limit, thescope of the present invention.

EXAMPLES

A gradient pattern is prepared using Adobe Photoshop® Elements software.The gradient pattern is 319 pixels wide by 1200 pixels long, andincreases progressively from 100 to 0% black. An image of this gradientpattern is set forth as FIG. 1 a. An Adobe Photoshop® plug-in,commercially available from Xaar®, is used to convert the gradientpattern of FIG. 1 a into another gradient pattern including discretepixels based on inkjet droplet volume. An image of this gradient patternis set forth as FIG. 1 b. The gradient pattern of FIG. 1 b can beprinted at eight different drop volumes using an Omnidot 318 printhead.The gradient pattern of FIG. 1 b is then converted with the same AdobePhotoshop® plug-in to yet another gradient pattern to be printed. Animage of this gradient pattern is set forth as FIG. 1 c. This gradientpattern is based on inkjet droplet volume and droplet placement. Thegradient patterns are saved as a bitmap files at 300 pixel resolutionand 24 bit color.

To initially evaluate the gradient pattern of FIG. 1 c to be printed, aXenjet® 4000 industrial inkjet printer is used to dispense droplets ofcommercially available black ink onto a substrate (i.e., photopaper) ina single pass. As is well known in the art of inkjet printing, thedroplets are dispensed onto the substrate with lateral spacing betweendroplets (i.e. spacing between rows of droplets on the substrate) thatis defined by a pitch (e.g. ˜169 μm) of a nozzle plate of the inkjetprinter. An illustrative example of droplets of black ink dispensed ontophotopaper as rows of droplets, as viewed through an optical microscope,is set forth as FIG. 2 a. A continuous film of droplets is set forth asFIG. 2 b as also viewed through an optical microscope, and may beprepared by customizing the substrate to allow the droplets to morecompletely wet and spread out. The inkjet printer may also make multiplepasses (e.g. ˜4) over a single area of the substrate with a slightlyoffset printhead (e.g. ˜50 μm) per pass to dispense the droplets ontothe substrate and form the continuous film.

The gradient pattern of FIG. 1 c is printed onto photopaper using theXenjet® 4000 inkjet printer and a single commercially available blackink. The inkjet printer makes four passes over a single area of thephotopaper utilizing a printhead that is offset 50 μm per pass. Theprinted gradient pattern is evaluated to determine ink density every 20mm intervals along the gradient pattern using an optical microscope. Theresults of this evaluation, set forth as the optical micrographs in FIG.3, indicate that a density of deposited ink decreases from left to rightacross the photopaper and across the micrographs. The opticalmicrographs illustrate that the Xenjet® 4000 inkjet printer successfullyprints gradient patterns.

A Xenjet® 4000 industrial inkjet printer having two printheadscommercially manufactured by Xaar® is used to print the gradient patternof FIG. 1 c onto a substrate in a nitrogen purged atmosphere to minimizeoxygen inhibition. More specifically, a first printhead includes anorganoborane-amine complex as the organoborane initiator and a radicalcurable component including a mixture of a first and a second radicalpolymerizable (curable) monomer. A second printhead includes adecomplexing component and an additional amount of the first radicalpolymerizable monomer. The specific identities of the organoborane-aminecomplex, the first and second radical polymerizable monomers of theradical curable component, and decomplexing component are set forth inTable 1 below.

TABLE 1 Weight Percent Commercial (%) Supplier First Printhead Butyleneglycol dimethacrylate 65.3 Ciba (1^(st) monomer of the radical curablecomponent) Trimethylolpropane trimethacrylate 24 Ciba (2^(nd) monomer ofthe radical curable component) Tributylborane-methoxypropylamine 10 AkzoNobel (organoborane-amine complex) Orcosolve Black RE dye 0.5 OrcoBNX-2000 hydroxyl amine stabilizer 0.2 Mayzo Second Printhead Butyleneglycol dimethacrylate 69.5 Ciba (1^(st) monomer of the radical curablecomponent) 2-carboxyethyl acrylate 30 Ciba (decomplexing component)Orcosolve Black RE dye 0.5 Orco

To initially evaluate the ability of the Xenjet® 4000 industrial inkjetprinter and the two printheads to dispense the organoborane-aminecomplex, the radical curable component, and decomplexing component ontothe substrate, and to ensure that curing can occur on the substrate, a100% black image is printed on an uncoated side of a polyethyleneterephthalate (PET) inkjet transparency using the first and secondprintheads simultaneously. Four passes are made by the inkjet printerover the PET inkjet transparency with the first and second printheadsoffset by 50 μm per pass. These passes form a film of overlappingdroplets of the organoborane-amine complex, the radical curablecomponent, and decomplexing component. The droplets mix on the surfaceof the PET inkjet transparency resulting in polymerization of the firstand second radical polymerizable monomers of the radical curablecomponent and curing of the film. The cured film does not include anyresidual amount of either the first or second radical polymerizablemonomers of the radical curable component. The formation of the curedfilm indicates that the Xenjet® 4000 inkjet printer successfullydispenses the organoborane-amine complex, the radical curable component,and decomplexing component onto the substrate and that cure can occur onthe substrate.

Example 1

The gradient pattern of FIG. 1 c is printed on an uncoated side of apolyethylene terephthalate (PET) inkjet transparency using the Xenjet®4000 industrial inkjet printer utilizing the first printhead. Fourpasses are made over the PET inkjet transparency while offsetting thefirst printhead by 50 μm per pass. Then, a 100% black image is printedon top of the gradient pattern utilizing the second printhead. Fourpasses are made over the gradient pattern while offsetting the secondprinthead by 50 μm per pass. The printing occurs in a nitrogen purgedatmosphere to minimize oxygen inhibition. The four passes from each ofthe first and second printheads results in different mix ratios of theorganoborane-amine complex, the first and second radical polymerizablemonomers of the radical curable component, and the decomplexingcomponent across the PET inkjet transparency. After printing, a portionof the gradient pattern that includes the highest concentration of theorganoborane-amine complex is determined to be well cured through visualevaluation. A portion of the gradient pattern with the lowestconcentration of the organoborane-amine complex is determined to beuncured through visual evaluation and is easily rubbed off of the PETinkjet transparency using a nitrile rubber gloved finger and manualsmearing.

Example 2

The gradient pattern of FIG. 1 c is also printed on an uncoated side ofa polyethylene terephthalate (PET) inkjet transparency using the Xenjet®4000 industrial inkjet printer utilizing the second printhead. Fourpasses are made over the PET inkjet transparency while offsetting thesecond printhead by 50 μm per pass. Then, a 100% black image is printedon top of the gradient pattern utilizing the first printhead. Fourpasses are made over the gradient pattern while offsetting the firstprinthead by 50 μm per pass. The printing occurs in a nitrogen purgedatmosphere to minimize oxygen inhibition. The four passes from each ofthe first and second printheads results in different mix ratios of theorganoborane-amine complex, the first and second radical polymerizablemonomers of the radical curable component, and the decomplexingcomponent across the PET inkjet transparency. After printing, a portionof the gradient pattern that includes the highest concentration of thedecomplexing component is determined to be well cured through visualevaluation. A portion of the gradient pattern with the lowestconcentration of the decomplexing component is determined to be uncuredthrough visual evaluation and is easily rubbed off of the PET inkjettransparency using a nitrile rubber gloved finger and manual smearing.

Example 3

An Epson Stylus Photo R220 office inkjet printer is used to form agradient pattern on a substrate. More specifically, two empty fluidcartridges are purchased and filled separately with a solution of about100 wt % acrylic acid in the first cartridge and a solution of about 5wt % triethylborane-propanediamine (TEB-PDA) in isopropanol in thesecond cartridge. In this Example, the acrylic acid functions as boththe radical curable component and the decomplexing component. An imageis prepared in Microsoft Paint that contains discrete portions of agradient pattern corresponding to surface coverages of acrylic acid offrom 100 to 0% overlaid on a pattern of surface coverage of from 0 to100% for TEB-PDA. The color of the pattern corresponds to the color ofthe fluid cartridge that contains the acrylic acid. The solution isprinted onto an inkjet transparency resulting in a pattern of acrylicacid and TEB-PDA mixtures with surface coverage varying according to thegradient pattern. After printing, a portion of the gradient pattern thatincludes the highest concentration of the TEB-PDA is determined to bewell cured through visual evaluation. A portion of the gradient patternwith the lowest concentration of the TEB-PDA is determined to be uncuredthrough visual evaluation.

Examples 1-3 demonstrate that the method of the instant invention can beused to quickly determine a proper mixing ratio of the organoboraneinitiator, the radical curable component, and optionally, thedecomplexing component, to form an article having a gradient patternformed thereon. These Examples also demonstrate that this method can beused to rapidly screen a range of compositions to determine variousperformance properties such as extent of cure. It is readily envisionedthat various surface analytical techniques and property measurementtechniques may be used to correlate properties and compositions withvarious positions along gradient patterns.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology which has been used is intended to bein the nature of words of description rather than of limitation.Obviously, many modifications and variations of the present inventionare possible in light of the above teachings, and the invention may bepracticed otherwise than as specifically described.

1. A method of preparing a substrate with a composition comprising (i)an organoborane initiator and (ii) a radical curable component, saidmethod comprising the step of individually printing (i) the organoboraneinitiator and/or (ii) the radical curable component onto the substratewherein at least one of (i) the organoborane initiator and (ii) theradical curable component is individually printed onto the substrate inthe form of a gradient pattern.
 2. A method as set forth in claim 1wherein the composition further comprises (iii) a decomplexing componentand (iii) the decomplexing component is printed onto the substrate incombination with at least one of (i) the organoborane initiator and (ii)the radical curable component.
 3. A method as set forth in claim 2wherein (i) the organoborane initiator is further defined as a complexof an organoborane and an amine.
 4. A method as set forth in claim 1wherein the step of individually printing is further defined as digitalprinting.
 5. A method as set forth in claim 4 wherein the step ofdigital printing is further defined as ink-jet printing.
 6. A method asset forth in claim 2 wherein (i) the organoborane initiator, (ii) theradical curable component, and (iii) the decomplexing component are eachindividually printed onto the substrate.
 7. A method as set forth inclaim 6 wherein (i) the organoborane initiator is printed before (ii)the radical curable component and (iii) the decomplexing component.
 8. Amethod as set forth in claim 6 wherein (iii) the decomplexing componentis printed before (i) the organoborane initiator and (ii) the radicalcurable component.
 9. A method as set forth in claim 6 wherein (ii) theradical curable component is printed before (i) the organoboraneinitiator and (iii) the decomplexing component.
 10. A method as setforth in claim 2 wherein the step of individually printing theorganoborane initiator is further defined as individually printing afirst mixture comprising (i) the organoborane initiator and a firstradical curable component and the step of individually printing theradical curable component is further defined as individually printing asecond mixture comprising a second radical curable component and (iii)the decomplexing component.
 11. A method as set forth in claim 1 wherein(ii) the radical curable component comprises a radical curableorganosilicon compound.
 12. A method as set forth in claim 11 whereinthe radical curable organosilicon compound is selected from the group ofan organosilane, an organopolysiloxane, and combinations thereof.
 13. Amethod as set forth in claim 1 wherein (ii) the radical curablecomponent comprises an acrylic compound.
 14. A method as set forth inclaim 1 wherein (i) the organoborane initiator is further defined as acomplex of an organoborane and an amine and wherein the organoborane hasthe general structure:

wherein each of R¹-R³ is independently selected from a group of ahydrogen atom, an aliphatic hydrocarbon group, and an aromatichydrocarbon group, with each of the hydrocarbon groups independentlyhaving from 1 to 20 carbon atoms.
 15. A method as set forth in claim 14wherein the organoborane is selected from the group of tri-methylborane,tri-ethylborane, tri-n-butylborane, tri-n-octylborane,tri-sec-butylborane, tridodecylborane, phenyldiethylborane, andcombinations thereof.
 16. A method as set forth in claim 14 wherein theamine is selected from the group of amine-functional silanes,amine-functional organopolysiloxanes, and combinations thereof.
 17. Amethod as set forth in claim 1 wherein (i) the organoborane initiator isfurther defined as an organoborane-amine complex.
 18. A method as setforth in claim 2 wherein (iii) the decomplexing component is furtherdefined as an organonitrogen reactive compound that is selected from thegroup of silanes, organosiloxanes, and combinations thereof.
 19. Amethod as set forth in claim 2 wherein (iii) the decomplexing componentis further defined as an organonitrogen reactive compound that isselected from the group of isophorone diisocyanate, acrylic acid,methacrylic anhydride, undecylenic acid, citraconic anhydride,polyacrylic acid, and combinations thereof.
 20. A method as set forth inclaim 1 wherein the gradient pattern is further defined as surfacecoverage of at least one of (i) the organoborane initiator and (ii) theradical curable component on the substrate increasing progressively from0 to 100% along a first axis.
 21. A method as set forth in claim 20wherein the gradient pattern is further defined as surface coverage of(iii) a decomplexing component on the substrate increasing progressivelyfrom 0 to 100% along a second axis transverse to the first axis.
 22. Amethod as set forth in claim 2 wherein the gradient pattern is furtherdefined as surface coverage of at least one of (i) the organoboraneinitiator, (ii) the radical curable component, and (iii) thedecomplexing component on the substrate increasing progressively from 0to 100% along a first axis.
 23. A method as set forth in claim 22wherein the gradient pattern is further defined as surface coverage ofat least one of (i)-(iii) on the substrate increasing progressively from0 to 100% along a second axis transverse to the first axis, so long asthe at least one of (i)-(iii) along the second axis is not the same asthe at least one of (i)-(iii) along the first axis.
 24. A method as setforth in claim 1 further comprising the step of analyzing the gradientpattern.
 25. A method as set forth in claim 2 wherein the decomplexingcomponent comprises 2-carboxyethyl acrylate.